PetroChina Coalbed Methane Company Limited
College of Mining Engineering, Taiyuan University of Technology

【目的】三交区块8+9号煤层气井受外来水侵入影响导致产能较差,因此厘清三交区块水文地质特征、查明其对煤层气井开发的影响成为煤层气产能突破的关键。【方法】基于实际地质和生产资料,收集水化学数据,采用Fisher判别方法进行水源判识,进一步利用测井解释对太原组各含水层分布及其含水性进行识别,最终实现了8+9号煤储层水文地质条件的精细化研究。【结果】研究结果表明,煤层气井主要生产太原组灰岩水,局部由于受到张性走滑断层的控制,水化学特征显示为太原组灰岩和二叠系砂岩混合水;太原组8号顶板发育L1-L5共5套灰岩层,灰岩发育总体比较稳定,局部存在分叉合并现象,北部明显减薄;5套灰岩的富水性在垂向上和平面上都存在明显的非均质性。【结论】针对灰岩不同发育程度和富水性强弱的区域,应采用相对应的开发策略,以保证煤层气井的高效开发。本次研究对厘清三交区块水文地质特征、指导后续开发部署等都具有非常重要的意义。

【Purposes】 The productivity of 8+9# coalbed methane wells in Sanjiao Block is poor owing to the intrusion of external water. Therefore, clarifying the hydrogeological charac-teristics and identifying its impact on the coalbed methane (CBM) development have become the key to increasing CBM production capacity. 【Methods】 On the basis of actual geological and pro-duction data, Fisher discriminant theory is used to identify water sources, and logging interpreta-tion is further used to identify the distribution and water content of each aquifer in the Taiyuan Formation. An advanced study is ultimately achieved on the hydrogeological conditions of the 8+9# coal reservoirs. 【Findings】 The results show that the water from the CBM wells is mainly from the limestone in the Taiyuan Formation, partially showing the mixed water from Taiyuan Formation limestone and Permian sandstone, which is induced by the tensile strike-slip faults. There are five sets of limestone layers (L1-L5) developed on the coal seam 8# roof. The lime-stone development is generally stable with local branching and merging phenomena, and the northern part is significantly thinner. The five sets of limestone have obvious heterogeneity both vertically and horizontally in terms of water content. 【Conclusions】 Targeted development tech-nology should be adopted in areas with different limestone development and water content. This study is of great significance for clarifying the hydrogeological characteristics and guiding the CBM development and deployment.

山西省青年科学基金资助项目(202103021223034)

王峰,常锁亮,闫欣璐,等.三交区块8+9号煤层气储层水文地质条件及水源判识研究[J].太原理工大学学报,2023,54(4):673-683.

WANG Feng,CHANG Suoliang,YAN Xinlu,et al.Study on hydrogeological conditions and water source identi-fication of 8+9# coalbed methane reservoir in Sanjiao Block[J].Journal of Taiyuan University of Technology,2023,54(4):673-683.